A High Flux Source of Cold Rubidium

We report the production of a continuous, slow, and cold beam of 87-Rb atoms with an unprecedented flux of 3.2 x 10^12 atoms/s and a temperature of a few milliKelvin. Hot atoms are emitted from a Rb candlestick atomic beam source and transversely cooled and collimated by a 20 cm long atomic collimator section, augmenting overall beam flux by a factor of 50. The atomic beam is then decelerated and longitudinally cooled by Zeeman slowing

Molecular Line Emission from Gravitationally Unstable Protoplanetary Disks

In the era of high resolution submillimeter interferometers, it will soon be possible to observe the neutral circumstellar medium directly involved in gas giant planet (GGP) formation at physical scales previously unattainable. In order to explore possible signatures of gas giant planet formation via disk instabilities, we have combined a 3D, non-local thermodynamic equilibrium (LTE) radiative transfer code with a 3D, finite differences hydrodynamical code to model molecular emission lines from the vicinity of a 1.4 M_J self-gravitating proto-GGP. Here, we explore the properties of rotational transitions of the commonly observed dense gas tracer, HCO+. Our main results are the following: 1. Very high lying HCO+ transitions (e.g. HCO+ J=7-6) can trace dense planet forming clumps around circumstellar disks. Depending on the molecular abundance, the proto-GGP may be directly imageable by the Atacama Large Millimeter Array (ALMA). 2. HCO+ emission lines are heavily self-absorbed through the proto-GGP's dense molecular core. This signature is nearly ubiquitous, and only weakly dependent on assumed HCO+ abundances. The self-absorption features are most pronounced at higher angular resolutions. Dense clumps that are not self-gravitating only show minor self-absorption features. 3. Line temperatures are highest through the proto-GGP at all assumed abundances and inclination angles. Conversely, due to self-absorption in the line, the velocity-integrated intensity may not be. High angular resolution interferometers such as the Submillimeter Array (SMA) and ALMA may be able to differentiate between competing theories of gas giant planet formation.Comment: 10 pages, 13 figures; Accepted by Ap

Dynamical mechanism of atrial fibrillation: a topological approach

While spiral wave breakup has been implicated in the emergence of atrial fibrillation, its role in maintaining this complex type of cardiac arrhythmia is less clear. We used the Karma model of cardiac excitation to investigate the dynamical mechanisms that sustain atrial fibrillation once it has been established. The results of our numerical study show that spatiotemporally chaotic dynamics in this regime can be described as a dynamical equilibrium between topologically distinct types of transitions that increase or decrease the number of wavelets, in general agreement with the multiple wavelets hypothesis. Surprisingly, we found that the process of continuous excitation waves breaking up into discontinuous pieces plays no role whatsoever in maintaining spatiotemporal complexity. Instead this complexity is maintained as a dynamical balance between wave coalescence -- a unique, previously unidentified, topological process that increases the number of wavelets -- and wave collapse -- a different topological process that decreases their number.Comment: 15 pages, 14 figure

Biomarkers of Myocardial Stress and Systemic Inflammation in Patients Who Engage in Heart Failure Self-Care Management

Background: Self-care is believed to improve heart failure (HF) outcomes, but the mechanisms by which such improvement occurs remain unclear. Methods: We completed a secondary analysis of cross-sectional data collected on adults with symptomatic HF to test our hypothesis that effective self-care is associated with less myocardial stress and systemic inflammation. Multivariate logistic regression modeling was used to determine if better HF self-care reduced the odds of having serum levels of amino-terminal pro-B-type natriuretic peptide and soluble tumor necrosis factor α receptor type 1 at or greater than the sample median. Heart failure self-care was measured using the Self-care of Heart Failure Index. Results: The sample (n = 168) was predominantly male (65.5%), and most (50.6%) had New York Heart Association III HF (mean left ventricular ejection fraction, 34.9% [SD, 14.0%]); mean age was 58.8 (SD, 11.5) years. Self-care management was an independent factor in the model (block χ2 = 14.74; P = .005) after controlling for pertinent confounders (model χ2 = 52.15; P \u3c .001). Each 1-point increase in self-care management score (range, 15-100) was associated with a 12.7% reduction in the odds of having levels of both biomarkers at or greater than the sample median (adjusted odds ratio, 0.873; 95% confidence interval, 0.77-0.99; P = .03). Conclusion: Better self-care management was associated with reduced odds of myocardial stress and systemic inflammation over and above pharmacological therapy and other common confounding factors. Teaching HF patients early symptom recognition and self-care of symptoms may decrease myocardial stress and systemic inflammation

Colorectal EMR outcomes in octogenarians versus younger patients referred for removal of large (≥20 mm) nonpedunculated polyps

Background and Aims Data are limited on safety and outcomes of colorectal EMR in octogenarians (≥80 years old). We sought to review outcome data for patients aged ≥80 in a prospectively collected database of patients referred for large polyp removal. Methods We retrospectively evaluated a database of patients referred for large (≥20 mm) nonpedunculated polyp removal. From 2000 to 2019, we compared the rates of follow-up, recurrence, adverse events, and synchronous neoplasia detection between younger patients and patients aged ≥80. Results There were 167 patients aged ≥80 years and 1686 <80 years. Patients in the elderly group returned for surveillance less often (67.1% vs 75.1%, P = .024), had greater first follow-up recurrence rates (27.5% vs 13.8%, P < .001), but had similar adverse event rates (1.8% vs 2.8%, P = .619) compared with younger patients. Rates of synchronous neoplasia were similar and high in both groups. Conclusions EMR is safe and well tolerated for large polyp removal in patients over 80 years old. Patients aged ≥80 years are less likely to present for follow-up after EMR. They had a higher recurrence rate and a similarly high prevalence of synchronous precancerous lesions. Follow-up after EMR should be encouraged in the elderly, and an attempt to clear the colon of synchronous disease at the time of the initial EMR may be warranted

Landscape Epidemiology and Control of Pathogens with Cryptic and Long-Distance Dispersal: Sudden Oak Death in Northern Californian Forests

Exotic pathogens and pests threaten ecosystem service, biodiversity, and crop security globally. If an invasive agent can disperse asymptomatically over long distances, multiple spatial and temporal scales interplay, making identification of effective strategies to regulate, monitor, and control disease extremely difficult. The management of outbreaks is also challenged by limited data on the actual area infested and the dynamics of spatial spread, due to financial, technological, or social constraints. We examine principles of landscape epidemiology important in designing policy to prevent or slow invasion by such organisms, and use Phytophthora ramorum, the cause of sudden oak death, to illustrate how shortfalls in their understanding can render management applications inappropriate. This pathogen has invaded forests in coastal California, USA, and an isolated but fast-growing epidemic focus in northern California (Humboldt County) has the potential for extensive spread. The risk of spread is enhanced by the pathogen's generalist nature and survival. Additionally, the extent of cryptic infection is unknown due to limited surveying resources and access to private land. Here, we use an epidemiological model for transmission in heterogeneous landscapes and Bayesian Markov-chain-Monte-Carlo inference to estimate dispersal and life-cycle parameters of P. ramorum and forecast the distribution of infection and speed of the epidemic front in Humboldt County. We assess the viability of management options for containing the pathogen's northern spread and local impacts. Implementing a stand-alone host-free “barrier” had limited efficacy due to long-distance dispersal, but combining curative with preventive treatments ahead of the front reduced local damage and contained spread. While the large size of this focus makes effective control expensive, early synchronous treatment in newly-identified disease foci should be more cost-effective. We show how the successful management of forest ecosystems depends on estimating the spatial scales of invasion and treatment of pathogens and pests with cryptic long-distance dispersal

Genome of Drosophila suzukii, the spotted wing drosophila.

Drosophila suzukii Matsumura (spotted wing drosophila) has recently become a serious pest of a wide variety of fruit crops in the United States as well as in Europe, leading to substantial yearly crop losses. To enable basic and applied research of this important pest, we sequenced the D. suzukii genome to obtain a high-quality reference sequence. Here, we discuss the basic properties of the genome and transcriptome and describe patterns of genome evolution in D. suzukii and its close relatives. Our analyses and genome annotations are presented in a web portal, SpottedWingFlyBase, to facilitate public access

Urinary ATP and visualization of intracellular bacteria: a superior diagnostic marker for recurrent UTI in renal transplant recipients?

Renal transplant recipients (RTR) are highly susceptible to urinary tract infections (UTIs) with over 50% of patients having at least one UTI within the first year. Yet it is generally acknowledged that there is considerable insensitivity and inaccuracy in routine urinalysis when screening for UTIs. Thus a large number of transplant patients with genuine urine infections may go undiagnosed and develop chronic recalcitrant infections, which can be associated with graft loss and morbidity. Given a recent study demonstrating ATP is released by urothelial cells in response to bacteria exposure, possibly acting at metabotropic P2Y receptors mediating a proinflammatory response, we have investigated alternative, and possibly more appropriate, urinalysis techniques in a cohort of RTRs.Mid-stream urine (MSU) samples were collected from 53 outpatient RTRs. Conventional leukocyte esterase and nitrite dipstick tests, and microscopic pyuria counts (in 1 ?l), ATP concentration measurements, and identification of intracellular bacteria in shed urothelial cells, were performed on fresh unspun samples and compared to ‘gold-standard’ bacterial culture results.Of the 53 RTRs, 22% were deemed to have a UTI by ‘gold-standard’ conventional bacteria culture, whereas 87%, 8% and 4% showed evidence of UTIs according to leukocyte esterase dipstick, nitrite dipstick, and a combination of both dipsticks, respectively. Intracellular bacteria were visualized in shed urothelial cells of 44% of RTRs, however only 1 of the 23 RTRs (44%) was deemed to have a UTI by conventional bacteria culture. A significant association of the ‘gold-standard’ test with urinary ATP concentration combined with visualization of intracellular bacteria in shed urothelial cells was determined using the Fisher’s exact test.It is apparent that standard bedside tests for UTIs give variable results and that seemingly quiescent bacteria in urothelial cells are very common in RTRs and may represent a focus of subclinical infection. Furthermore, our results suggest urinary ATP concentration combined with detection of intracellular bacteria in shed urinary epithelial cells may be a sensitive means by which to detect ‘occult’ infection in RTRs